Mobile communications networks are evolving rapidly at the present. Different operators are competing on the market, each of which has to provide an as complete network coverage as possible. Investment in network hardware is one of the largest costs when establishing mobile communications networks. Traditionally, each operator has provided his own network hardware. Fairly recently, network infrastructure sharing has been proposed as a means to enable a number of network operators to minimise costs associated with rolling out networks. A number of different approaches for sharing network resources have been proposed, such as: geographical shared networks, site sharing, shared UTRAN and common shared network. More details on the architecture of the different approaches to sharing are available in [1].
In shared networks, one or more operators share at least some infrastructure to deliver services to users. Hence, resources are shared on that part of the infrastructure that is shared to deliver the desired services. In some situations, there can be sharing of constrained resources. Sharing of such limited resources requires some thought and it is necessary to devise an approach for sharing these resources which is fair to all of the operators involved but yet maximises the utilisation of the constrained resource.
Shared networks are a relatively new concept and have not yet reached deployment status. Some modifications have been made to standards to facilitate development of shared networks. For example, it was necessary to modify standards to facilitate geographic network sharing such that a single infrastructure could look like more than one infrastructure. Product development work to date has focused on modifying existing solutions, which were developed for non-sharing contexts, to operate in a shared networking context. As such, little extra functionality or features have been added which is specific to the shared networking environment.
In relation to the specific issues associated with managing constrained resources in shared networks, no prior art solutions are known. However, one simple approach to manage the resources is to ignore the fact that the infrastructure is being shared and to allocate the resources as they are requested if there are sufficient resources available. However, this can result in an unfair distribution of resources. For example, if two operators are sharing the resources, each of which pays for 50% of the network rollout costs. Assume there is an agreement between the operators that both of them are entitled to 50% of the resources during congested periods. If, for some reason, there are greater demands for service amongst the customers of one operator, this operator can obtain a higher fraction of the resources than the agreed 50%.